1. Field of the Invention
The present invention relates to feeding and tightening of threaded parts such as bolts and nuts to, depending on the parts, threaded holes or bolts (hereinafter called objects) at a desired location, with the purpose of realizing generally used bolt runners or nut runners as automatic machines.
2. Prior Art
As far as the present inventor investigated the literature there is no prior art exactly corresponding to the present invention, but generally a rotatable feed rod capable of reciprocating movement holds a threaded part at its front end, and carries the threaded part to the object by moving along a specified path while avoiding surrounding machines and devices. When the feed rod moves along such a specified path with the threaded part at its front end, the feed rod moves in the axial direction or then suddenly moves in a direction orthogonal to the axial direction, and therefore, the threaded part being held is caused to move suddenly or stop abruptly, and can be accidentally shaken off the front end of the feed rod or deviated in position due to the inertial force. Such problems as described are particularly significant in a robot apparatus of the like.